Light heads at a street intersection generally each include various lights, such as one or more red lights, one or more yellow lights, one or more green lights, one or more turn signal lights, etc. A typical vehicle traffic signal control system includes a control box located near an intersection at which one or more light heads are located. The control box typically includes components for controlling which lights of the light head(s) are enabled and which lights of the light head(s) are disabled. For example, the control box may include a controller, a power distribution module, relays, and a conflict monitor.